Dial for radio apparatus



Dec. 6, 1938. E. KONIG DIAL FOR RADIO APPARATUS Filed Oct. 22, 1935 INVENTOR. ERWIN KoNlG ATTORNEY.

Patented Dec. 6', 1938 UNITED STATES 7 2,139,451 mar; roa RADIO AIPPARATUS Erwin Konig, Berlin-Neukoelln, Germany, as-

signorto- Allgemeine Elektricitats Gesellschaft, Berlin, Germany, a corporation of Germany Application October 22, 1935, Serial No. 46,111

In Germany November 7, 1934 4 Claims.

This invention relates to a dial for radio apparatus which affords a rapid and simple setting of the tuning means to a desired station.

Dials are already known in which the individ- 'ual station names classified in wave lengths are divided into groups, while for selecting the desired group of transmitters a separate list such as a station alphabet is employed. These dials have the disadvantage that they lack consider- 10 ably in clearness. The great number of station names listed in accordance with the frequency or Wave-length brings confusion, renders difficult the selection and the setting to a definite station while not excluding the possibility of errors.

In accordance with this invention the total number of the station names is subdivided into groups. The individual groups are so arranged on the dial that always only one group appears in a window at which place it is suitably illuminated by direct light or through'transparency. The dial which carries the station names is so mechanically connected with the tuning means. that the latter are automatically set to a desired group of transmitters, when the names of this group appear in the window, so that only a fine adjustment is required in order to receive immediately a definite transmitter of the group through the loudspeaker. The arrangement is such that the individual groups are designated by letters so that they can be selected in the manner of the automatic phone dial when making a call. Within each group the station names are identified by means of a reference number.

The setting to a definite transmitter on the dial is done in such manner that the identification letter and identification number are determined from the station list, whereafter for instance by turning a knob the tuning means and the dial disk are set to the letter thereby obtaining directly the corresponding sub group and then the setting to the identification number of said station is carried out by means of a fine or Vernier adjustment element. This setting is very simple and rapid and excludes any errors.

The station name is read within each group by means of a single indicator especially assigned thereto such as, for instance, a graduation curve traced on a disk which is connected with the tuning means.

50 In accordance with a further feature of the invention, the arrangement is such that a loose mechanical coupling is provided between the said two setting or control devices. This may be accomplished for instance in that the setting 55 device for the identification number is connected with a disk or a band carrying the graduation curves or indicators for the individual transmitters, whereas the individual groups of transmitters are listed on another disk or on another band. If the graduation curve of one group has been moved past all station names, the tuning control of the indicator disk, due to the loose mechanical coupling, moves therewith the part having the groups of transmitters, for example by means of special cams or notches in the indi- 10 catordisk, thus obtaining automatically a more rapid setting of the tuning means than would be possible by a simple rotation of the setting control.

For a better understanding of the invention, 15 reference is made to the accompanying drawing in which:

Fig. 1 is a perspective view of a portion of the frontpanel of a radio receiver embodying the invention; 0

Fig. 2 is a, perspective View showing the control and indicating device of Fig. 1 with the panel removed and,

Fig. 3 is a front view of the Vernier control disk of Fig. 2, and Fig. 4 is a vertical sectional. view taken through the line 4--4 of Fig. 1 but omitting the panel and tuning condenser.

Referring to the drawing,numeral l is a disk or indicator carrying the graduation curves [0 for the several transmitting stations and is rigidly secured to the tuning condenser shaft l3. On the disk 2 in front thereof, the station names are symmetrically listed in groups, the disk 2 and its attached gear wheel 5a being loosely mounted for free rotation on condenser shaft l3. As seen 3 from Fig. 1 of the drawing, there appears of these station names in the window ll formed in a plate 3 always only one group, while all remaining groups remain concealed behind plate 3 and its supporting panel I2. At the right and the 40 left of this window the names of all stations which can be received by the receiver are alphahetically listed on a plate 3 secured to main panel l2. The two manual control knobs are designated by 6 and l. The variable tuning condenser having a rotor shaft i3 is designated by 8. The handle 1 is fastened on the one hand to the rotor shaft 3 of variable condenser 8, and on the other hand, to the disk I. The gear 5a is fixedly secured to the disk 2 both these members being loosely mounted for free rotation on shaft I 3, while the gear 5b serves only for the transmission and rotates freely on a shaft l4. Gear 50 is rigidly connected with the switching wheel 4 and serves to rotate gear 5a and its attached disk 2 through the idler gear 5!), gear 50 and its attached wheel 4 being loosely mounted for free rotation on shaft Il carrying the control knob 6. Disk I is driven by the knob 6 and a friction wheel 5d secured to the shaft I1 and contacting disk I. The disk I is provided with a plurality of spaced lugs I6, as shown in Figs. 3 and 4. The lugs I6 are provided in the periphery of disk I by cutting a notch I6 therein, and bending the portion I6 at right angle to the plane of the disk. The lugs I6 point toward disk 2; and the wheel 4, provided with spaced teeth I5, is positioned on the face of disk I which is adjacent plate 2. The disk I has its lugs I6 arranged to move into successive contact with teeth I5, as shown in Fig. 4. The wheel 4 will be rotated each time a lug I6 is moved into contact with a tooth I5. Rotation of knob 6 will give a vernier adjustment of disk I, producing motion of the disk I between each pair of lugs I6 without shifting disk 2. If a large adjustment of shaft I3 is desired, this may be secured by rotating handle I which is directly secured thereto.

The disk 2 contains radially arranged apertures I8 alongside which the station names of transmitters having adjacent frequencies are marked. It will be understood that when the proper curve I is behind the aperture I8 and also opposite the number corresponding to a desired station, such station will be tuned in and operate the receiver. In the operation of the device, to change the tuning from a station in group A to one in group B, the knob 'I is rotated until letter B thereon comes opposite the index line marked on panel I2 as shown in Fig. 1. Since disk I and condenser shaft I3 are connected to the knob, they rotate therewith whereby a rough adjustment of the condenser to some frequency within the B group of stations is secured. As disk I rotates, one of its lugs I6 engages one of the teeth I of wheel 4 thereby rotating it and its attached gear 50. This causes idler gear 5b to in turn rotate gear 5a and its attached disk 2 to such a position that the B group of station names comes into view in window II. To select a particular station of this group,v the operator rotates knob 6, which, through the engagement of friction wheel Set with the rear surface of disk I, causes rotation of this disk until the curve I8 thereon which appears in slot I8 in disk 2, is directly opposite the desired station name. As clearly shown in Fig. 1, one of the curves III appears opposite station numbered 2 of group B indicating that the program from this station is being received. It will further be understood that while the curve on disk I is moving alongside the station names, the disk 2 is stationary since a lug IB' of disk I is out of engagement with the tooth I5 which it has just left. In other words the lugs I6 and teeth I5 provide anintermittent drive for disk 2 when the disk I is rotated by knob 1 through a rather large angle.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. Means for indicating the position of a tuning shaft, comprising the combination of a disk supported by said shaft, said disk having a plurality of groups of station names marked thereon, a. second disk secured to said shaft and having a separate index thereon for each group of station names, gearing connections between said disks, and a control knob mechanically connected to said second disk.

2. Means for indicating the position of a tuning shaft, comprising the combination of a disk mounted on said shaft, said disk having a plurality of apertures therein, a plurality of station indicia marked alongside each of said apertures, a rotatable member secured to said shaft behind said disk and having a plurality of indexes, each of which is arranged to register with a different one of said apertures, gearing connecting said rotatable member and disk and manual control means for adjusting said rotatable member.

3. A tuning indicator comprising in combination, a panel, a window opening in said panel, a tuning shaft passing through said panel, a handle secured to said shaft in front of said panel, a disk mounted on said shaft at the rear of said panel and having a plurality of groups of station indicia marked thereon, the station indicia of each separate group being arranged to lie behind said window opening, a second disk secured to said shaft at the rear of said panel and having a separate index adapted to cooperate with each group of said station indicia, gearing connecting said disks, a second shaft passing through said panel and connected to said second disk and a control handle secured to said second shaft in front of said panel.

4. Means for indicating the position of a tuning device comprising a shaft secured to said device, a disk secured to said shaft and provided with a plurality of apertures formed in its periphery, a second disk loosely mounted on said shaft and being marked with a plurality of radially arranged groups of station names, a wheel having a plurality of teeth adapted to successively enter said apertures and gearing connecting said wheel and second named disk.

ERWIN KCSNIG. 

